/*
 * Copyright (C) 2011 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.join.zxing.encode;

import java.util.Collection;
import java.util.HashSet;

/**
 * Implementations encode according to some scheme for encoding contact information, like VCard or
 * MECARD.
 *
 * @author Sean Owen
 */
public abstract class ContactEncoder {

    /**
     * @return first, the best effort encoding of all data in the appropriate format; second, a
     *   display-appropriate version of the contact information
     */
    public abstract String[] encode(Iterable<String> names, String organization,
            Iterable<String> addresses, Iterable<String> phones, Iterable<String> emails,
            Iterable<String> urls, String note);

    /**
     * @return null if s is null or empty, or result of s.trim() otherwise
     */
    public static String trim(String s) {
        if (s == null) {
            return null;
        }
        String result = s.trim();
        return result.length() == 0 ? null : result;
    }

    public static void doAppend(StringBuilder newContents, StringBuilder newDisplayContents,
            String prefix, String value, Formatter fieldFormatter, char terminator) {
        String trimmed = trim(value);
        if (trimmed != null) {
            newContents.append(prefix).append(':').append(fieldFormatter.format(trimmed))
                    .append(terminator);
            newDisplayContents.append(trimmed).append('\n');
        }
    }

    public static void doAppendUpToUnique(StringBuilder newContents,
            StringBuilder newDisplayContents, String prefix, Iterable<String> values, int max,
            Formatter formatter, Formatter fieldFormatter, char terminator) {
        if (values == null) {
            return;
        }
        int count = 0;
        Collection<String> uniques = new HashSet<String>(2);
        for (String value : values) {
            String trimmed = trim(value);
            if (trimmed != null && trimmed.length() > 0 && !uniques.contains(trimmed)) {
                newContents.append(prefix).append(':').append(fieldFormatter.format(trimmed))
                        .append(terminator);
                String display = formatter == null ? trimmed : formatter.format(trimmed);
                newDisplayContents.append(display).append('\n');
                if (++count == max) {
                    break;
                }
                uniques.add(trimmed);
            }
        }
    }

}
